In the image forming apparatus, the sheet is conveyed in the apparatus for image forming and so forth and then the sheet on which the image is formed is further conveyed inside the apparatus. Also the sheet is turned over as needed and conveyed (refer to Patent Document 1: Unexamined Japanese Patent Application Publication No. S61-222769 and Patent Document 2: Unexamined Japanese Patent Application Publication No. H7-43958). In Patent Document 1, there is disclosed a reverse device provided with a primary storing box to store the sheet printed on its obverse surface disposed in front of a hopper which selectively feeds the sheet one by one, a lateral direction reverse storing box, a longitudinal direction storing box and a reverse roller, wherein the sheet printed on its obverse surface is stored in the primary storing box via a changeover bar, then the sheet is stored in a lateral direction via a lateral direction reverse roller, and the sheet is sent to the longitudinal direction storing box, and then the sheet is turned over in the longitudinal direction by the longitudinal direction reverse roller, thereafter the sheet is sent to the reverse storing box in the longitudinal direction. In Patent Document 2, there is disclosed an image recording apparatus provided with a recording sheet reverse device which turns over the recording sheet 180° around a center line of the recording sheet width in a recording sheet proceeding direction as a rotation axis.
Incidentally, it is difficult to avoid a jam (paper jam) in a conveyance path including the reverse device in course of sheet conveyance. Therefore, a control section to control entire image forming apparatus detects the jam and stops the image forming apparatus when the jam is detected so that a user can remove the jammed sheet and a sheet remaining in the conveyance path.
Patent Document 1: Unexamined Japanese Patent Application Publication No. S61-222769
Patent Document 2: Unexamined Japanese Patent Application Publication No. H7-43958
However, with speeding up of the image forming function and to cope with a large size sheet, size of the image forming apparatus has increased, accordingly apparatuses to carry a large number of remaining sheets in side has appeared. Thus it leads a laborious job to address the jam and increasing down time. For example, if a jam occurs in an image forming apparatus configured with a plurality of units, to conduct jam processing, the plurality of the units has to be withdrawn respectively. Also since the locations of remaining sheets can not be recognized, there occurs a problem that a job to repeat the same operation many times occurs. Through in conventional apparatuses countermeasures to efficiently remove the jammed sheet and the remaining sheet from the apparatus have not been taken.